1. Field
The invention generally relates to cryptography and more particularly to authentication.
2. Description of the Related Art
Authentication involves some form of digital signature or message authentication code. Digital signatures and message authentication codes are based on public-key and/or symmetric-key cryptographic systems. The two systems have different characteristics, making one more applicable in one situation while the other more applicable in a different situation.
Generally, public-key systems have advantages in terms of key management and distribution. However, public key systems may often be computationally difficult and may involve large digital signatures. Accordingly, public key systems may require a powerful processor which may cause an increase in the cost, weight and/or size of a device; may require additional processing time which may cause delays, use more energy and/or drain batteries; or may cause a combination of the above results.
As a result, most small authentication devices have been forced, by both computational requirements and the need for small outputs, to use symmetric-key cryptography. However, with more and more capable processors in devices such as mobile phones, the computational requirements may no longer be a dominating factor. Nevertheless, there is still a need for a smaller digital signature.